When adding your first transaction in the system, a pop up will appear asking you to "Configure Default Account". This means, what account would you like to pre-fill each time you select the "Add Transaction" button?
The pop up will look like the below image, and allow you to select from each different managed account you have listed in the Inventory. As well as select your default "Money Type".
Your "Money Type" is in reference to either Principal/Income (USA) and Capital/Revenue (Canada).
This setting is changeable at anytime by selecting the "Account Configuration" option listed in the three dot menu on the top right corner of your Accounting screen.
Feel free to change it to ensure you don't have to choose your account or money type for each separate transaction!